Elevator systems



y 7, 1958 A. R. HOCKSTEIN ET AL 2,836,262

ELEVATOR SYSTEMS Filed April 4, 1957 v Sheets-Sheet 1 I3 I TSED, BTS1w l 39 P I6 55 Bl6 O O 0 o I MHHII O O O O 2DF I l I I IT B3T I B36 l9 l6 BIG 0 O O O W i i I -TLS SE 5 1%? fans 85E g M 5 E 1 IE u BIE g F|g I YID WITNESSES- INVENTORS Alfred R.Hockstein and John F. Hegurty.

ATTORNEY y 1958 A. R. HOCKSTEIN ET AL 2,836,262

ELEVATOR SYSTEMS Filed April 4, 1957 7 Sheets-Sheet 2 Elevator Control System Of Carney et al Patent 2 I72 I87 Modified As Shown Below LTAZ BIC3 B5C3 BXI BY 1 BI BM? 251% 5-00 8001 ,iBWI

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y 1958 A. R. HOCKSTEIN ET AL 2,836,262

ELEVATOR SYSTEMS Filed April 4, 1957 7 Sheets-Sheet 6 Fig.4.

United States Patent ELEVATOR SYSTEMS Alfred R. Hockstein and John F. Hegarty, Linden, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 4, 1957, Serial No. 650,732

Claims. (Cl. 187-29) This invention relates to elevator systems and it has particular relation to systems wherein elevator cars are parked when no elevator service is required.

In some elevator systems it is the practice to permit the elevator cars to move only when elevator service is required. When no elevator service is required the elevator cars park at suitable parking stations. Such an elevator system may provide an operation known as collective operation.

In a system designed to provide collective operation, a single floor-call push button may be provided on each floor served by an elevator car. If a call is registered for a floor by operation of the associated push button, the elevator car stops at such floor regardless of the direction in which the elevator car approached the floor. Carcall push buttons may be provided for registering calls desired by passengers in the elevator car. When designed for automatic operation, an elevator car is started in operation only when a call for service is registered in the system. When no call for service is registered, the elevator car remains parked at a floor.

A second elevator system may be designed to provide selective-collective operation. In such a system an up-fioor-call push button is provided at each floor from which elevator service in an up direction is desired. A down-floor-call push button is provided from each floor from which elevator service in the down direction is desired. When set for up travel an elevator car answers floor calls registered only by up-floor-call push buttons at least until the highest call of this type is answered. When set for down travel, the elevator answers floor calls registered only by the down-floor-call push buttons at least until the lowest call of this type is answered. Carcall push buttons also may be provided. The elevator ear is permitted to move only when acall is registered in the system. In the absence of a registered call for elevator service, the elevator car is parked at a suitable parking station.

In accordance with the invention an elevator car is parked at a selected one of a plurality of parking stations and the selection is changed under certain conditions to provide the most eificient operation of the elevator system. Thus, during a period wherein a demand for elevator service predominantly in the up direction is expected an elevator car in the absence of calls for service may be parked adjacent its lower terminal floor. During a period when elevator service may be expected predominantly in the down direction an elevator car in the absence of a call for service may be parked at a parking station located adjacent its upper terminal floor.

In accordance with the invention a parking station is selected automatically. In one embodiment of the invention the selection is based on traffic conditions or service demands. Thus, if a trafiic condition such as a substantial registration of up floor calls occurs, a parking station adjacent a lower terminal floor may be selected. Alternatively, a trafiic condition indicating a period of substan- 2,836,262 Patented May 27, 1958 tial demand for down elevator service, for example, regis' tration of a substantial number of down floor calls, may result in selection of a parking station adjacent the upper terminal floor.

Once a parking station has been selected in response to a service demand predominantly in a first direction, the parking station may be retained until a predetermined service demand occurs in a second directiom In another modification of the invention a primary parking station may be established and a secondary parking station becomes efiective only for a period determined by predetermined trafiic condition.

In some elevator installations the demand for elevator service follows a reasonably well-defined time pattern. For such an installation a timing mechanism may be employed for selecting different parking stations during different periods of time. p

The invention is applicable to an elevator installation employing a single elevator car. It is also desirable for an elevator system wherein a plurality of elevator, cars are arranged in a bank, and it will be described with particular reference to a bank of elevator cars.

It is, therefore, an object of the invention to provide an elevator system wherein a plurality of parking stations are provided for an elevator car and wherein a specific parking station is selected to be effective in response to.

a predetermined condition which occurs automatically during the operation of the elevator system.

It is a further object of the invention to provide an elevator system having a plurality of parking stations with a selector responsive to a traffic condition for determining which of the parking stations shall be effective.

It is also an object to provide an elevator system having a plurality of parking stations wherein a timing mechanism is provided for rendering each of the parking stations effective during a different period of time.

It is another object of the invention to provide an elevator system having a plurality of parking stations wherein one of the parking stations constitutes a primary parking station and wherein another parking station is efiective only for a period determined by the duration of a predetermined condition.

It is still a further object of the invention to provide an elevator system having a plurality of parking stations wherein each of the parking stations is efiective until occurrence of a predetermined condition results in selection of another parking station.

Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a diagrammatic representation of an elevator system embodying the invention;

Fig. 2 is a diagrammatic representation of a control circuit for the elevator system illustrated in Fig. 1;

Figs. 3 and 4 are diagrammatic representations in straight line form showing further a portion of the con trol circuits for the elevator system of Fig. 1, and

Figs. 2A, 3A and 4A are key illustrations of the relays embodied in Figs. 2, 3 and 4 respectively. If Figs. 2, 3 and 4 are horizontally aligned respectively with Figs. 2A, 3A and 4A, it will be found that the corresponding coils and contacts on the pairs of figures are substantially in horizontal alignment.

In order to simplify the presentation of the invention, the invention has been illustrated as applied to the elevator system of the Carney et al. Patent 2,172,187 which issued September 5, 1939. The entire system of the Carney et al. patent is incorporated herein with certain additions which will be discussed below. The conventions employed in the Carney et al. patent will be' followed herein.

Figure 1 s a...

Figure 1 of the drawings is identical with Fig. l of the Carney et al. patent with the exception of certain additions which will be discussed below. The reference characters in the present Fig. l for similar components are identical with those in the Carney et al. patent and designate the same components.

The only additions to Fig. l of the Carney et al. patent are represented for the elevator car A by the switches LS and TS. The switch LS is acam operated switch which is biased to closed position and which is opened by a cam TLS which is secured to the elevator car A only when the elevator car A is in a lower parking station which may be the first floor of the building served by the elevator car.

The switch TS is a cam operated switch which is normally biased to closed position and which is opened by the cam TLS only when the elevator car A is in an upper parking station which may be the fifth floor of the build ing served by the elevator car. Similar switches are provided for the elevator car B and for any other car incorporated in the system. In Fig. l the elevator car A is shown at the first floor whereas the elevator car B is shown at the third floor.

Figure 2 Figure 2 includes all the components of Figs. 3, 4 and of the aforesaid Carney et al. patent. The present Fig. 2 is intended to represent a system identical with that shown in Figs. 3, 4 and 5 of the Carney et al. patent with certain additions which will be discussed below. The present Fig. 2 illustrates, in detail, only Fig. 4 of the aforesaid Carney et al. patent, to which the additions are applied. The present Fig. 2 employs the same reference characters utilized in the Carney et al. patent to designate the same components. In certain cases, as

pointed out below, additonal contacts are provided for.

the relays of the Carney et al. patent.

Turning now to the additions which are shown in Fig. 2 in heavy lines, it will be noted that the car button 1B is shunted by an added circuit which includes, in series, the mechanically-operated switch LS and make contacts LTAl of a third parking relay LTA. The make contacts LTAl, in turn, are shunted through a circuit which contains break contacts UT3 of a first parking relay UT and a manually operated switch SW2.

The car button SE is shunted by a circuit which includes the mechanically-operated switch TS, make con tacts UTAI of a fourth parking relay and a single-pole, double-throw switch SW1. When the switch SW1 is operated to its second position it established a shunt around the carbutton 5B which includes the mechanically-operated switch TS, the switch SW1 and make contacts UTl of the first serve relay.

Similar additions are illustrated for the elevator car B.

Figures 3 and 4 Figures 3 and 4 show circuits for controlling the operation of the parking relays LT, UT, LTA, and UTA. These circuits include contacts which are added to certain relays of the Carney et al. patent. For example, for Fig. 3 make contacts 2C6 to 506 are added respectively to the car call registering relays 2C to 50 of the Carney et al. patent. Make contacts 1C7 to 4C7 are added respectively to the car call registering relays to of the Carney et al. patent. Make contacts lURS to dURS are added respectively to the up-floor call registering relays lUR to 4UR of the Carney et al. patent. Finally, make contacts 2DR8 to SDRS are added respectively to the down-floor call registering relays 2BR to SDR of the Carney et al. patent.

The first parking relay UT has its energization controlled by a stepping switch C0 which has a semi-circular row of contacts C01 to C011. The contacts are engaged by one of the brushes C010B to C011B which are dising relay UT is connected for encrgization.

' asaasea e 4 placed from each other degrees abouta shaft C012. The brushes are connected to the bus L- through break contacts RE7 of the reset relay RE.

The brushes COIOB and C011B are reset periodically to the positions illustrated in Fig. 3. The brushes are stepped by the shaft C012 in a clockwise direction for an angular distance corresponding to the spacing of successive contacts C01 to C011 for each registration of a call requiring down travel of an elevator car.

The first parking relay UT has one terminal connected to the bus L+ and its remaining terminal connected to a selected one of the contacts C01 to C011. The particular contact selected determines the number of stepping operations required of the brushes before the first park- For present purposes it will be assumed that the contact C04 is the selected contact. Consequently, the brushes must step three times from their reset positions before the first parking relay can be energized. During a resetting operation of the stepping relay the break contacts RE7 open to prevent energization of the first parking relay U1.

The stepping switch also has a second semi-circular row or bank of contacts C013 to C023 which are on gaged by one of two brushes C024 and C025, displaced from each other by 180 about the shaft C012. The brushes C024 and C023 are connected to the bus 12+. The contacts C013 to C022 are connected to the bus L- through a reset relay RE and either make contacts TA4 or make contacts RE3.

In order to step the shaft C012, a ratchet wheel C025 is secured thereto and a pawl C027 is positi ted to engage the ratchet wheel. This pawl is biased upwardly by means of a spring C028 to a position wherein the pawl C027 engages a stop C029.

The pawl C027 has a magnetic core C033 associated with a solenoid C031. The solenoid is connected for energizaton across the buses L+ and L- through a parallel circuit having a separate arm for each call which may be registered requiring travel in the down direction. For the purposes of illustration, circuits for the cars A and B have been illustrated.

An arm is provided for each car call which may be registered requiring down travel. For the elevator car A, arms are illustrated for the first 'to the fourth floors. One of the arms for the first floor contains the contacts 107, DP9 and 1CA1. Another arm for the fourth floor contains the contacts'4C7, DP6 and 4CA1. Thus, if a car call is registered intheelevator car A for the first fioor thecontacts 1C7 close. If the car is set for down travel thecontacts DP9 will be closed. Shortly after the contacts 1C7 close, the contacts 1CA1 open (as shown below) to provide a momentary pulse for the solenoid C031. A similar arm is provided for each intermediate floor, and corresponding arms are provided for each of the elevator cars. One of these arms is momentarily closed for each car call which is registered while the car in which the call is registered is set for down travel.

An arm is also provided for each down floor call which may be registered. Thus, one arm for the fifth floor contains make contacts 5DR8 of the up floor-call registering relay SDR and break contacts SDRAl which open shortly after the make contacts 5DR8 to close to provide a momentary circuit closure. A similar arm is provided for each down. call registering relay.

Each floor-call registering relay IUR to 4UR and 2DR to SDR' and each car call registering relay 10 to SC has make contacts controlling the energization of an auxiliary relay, respectively, .iURA to AURA, ZDRA. tr:- SDRA and 10A to 5CA. For example, the relay 4UR has make contacts 4UR9 controlling energization of the relay 4URA.

Consequently, for each registered down floor or car call, a pulse of'current is supplied to the solenoid C031 to attract the associated magnetic core C030 against the bias of the spring C028. Upon completion of the pulse,

5 the spring C028 urges the pawl C027 against the stop C029. During such movement, the pawl advances the shaft C012 one step. Each step of the shaft C012 corresponds to the angular distance between successive contacts C01 to C011 and C013 to C023.

For resetting purposes, the solenoid C031 is connected across the buses L+ and L through make contacts RES of the reset relay and self-stepping contacts C032 of the stepping switch. By inspection of Fig. 3, it will be observed that the contacts C032 are biased to their closed conditions by the spring C028 and are opened when the pawl C027 is moved down by the solenoid C031. Consequently, as long as the contacts RES remain closed, the stepping switch steps rapidly in a clockwise direction as viewed in Fig. 3. Such stepping switches are well known in the art. It will be noted 'that the contacts C023 are connected to the bus L+ through the self-stepping contacts C032.

The stepping switch COU associated with the relay LT is identical to the stepping switch CO with the exception that the parallel arms controlling stepping of the switch COU respond only to calls requiring up movement of the cars to make the stepping switch COU respond only to registered calls requiring travel of the elevator cars in the up direction. Similar components of the stepping switches C and COU are identified by similar reference characters except that the prefix COU rather than C0 is employed for reference characters associated with the switch COU.

As clearly shown in Fig. 3, the solenoid COU31 is connected across the buses L+ and L- through a parallel circuit having a separate arm for each registerable call requiring up travel of the elevator cars. Thus, for the elevator car A the solenoid COU31 is connected across the buses L+, L through a circuit including a plurality of parallel arms each including one of the sets of contacts 206 to 506, one of the sets of contacts UP6 to UP9 and one of the sets of contacts 2CA2 to CA2. The solenoid COU31 receives a pulse for each operation of a car call push button only if the car is set for up travel.

Similar circuits are shown for the elevator car B.

The solenoid COU31 may also be energized through an additional arm provided for each of the up floor-call registering relays in a manner analogous to the association of the solenoid C031 with the down floor-call registering relays. Thus, energizing arms are provided for the make contacts 4UR8, 3UR8, ZURS and 1UR8, respectively, which also include break contacts lURAl to 4URA1 respectively.

The stepping switches are reset at predetermined intervals. Such intervals are measured by an electronic tubeTB which has its anode electrode TBA and its cathode electrode TBK connected across the buses L+ and L through a timing relay TA and break contacts RE1 of the reset relay. The break contacts RBI also are connected in series with a resistor R8 and a capacitor CAP across the buses L+ and L. The tube TB has a control electrode TBC which is connected to a point between the resistor R8 and the capacitor CAP. A resistor R9 is connected through make contacts RE2 across the capacitor CAP. The tube TB may be of any desired type such as a hot-cathode, high-vacuum tube or a thyratron. For present purposes, it will be assumed that the tube is a cold-cathode gaseous-discharge tube.

When the break contacts REI close, the capacitor CAP starts to charge. After the lapse of a predetermined interval, the charge across the capacitor CAP becomes sufiicient to initiate a discharge in the tube TB. When the reset relay RE picks up, it opens its break contacts RBI to deenergize the timing relay TA and closes its make contacts RE2 to establish a discharge circuit for the capacitor CAP.

It is believed desirable at this point to describe a cycle of operations of certain circuits shown in Figs. 3 and 4. Let it be assumed that the components are in the conditions illustrated in Figs. 3 and 4, and that the break contacts REl have just reclosed to start the charging of the capacitor CAP.

As the capacitor CAP charges, it will be assumed that the elevator car A starts a down trip and that a down floor call is registered at the second floor. Also, the elevator car B starts an up trip and up floor calls are registered at the first, second and fourth floors.

As the down floor call is registered at the second floor, the make contacts ZDRS close to complete with the break contacts 2DRA1 an energizing circuit for the solenoid C031. Also, the contacts 2DR9 close to energize the auxiliary relay 2DRA. The auxiliary relay opens its contacts 2DRA1 to restrict the energization of the solenoid C031 to a brief pulse. In response to such energization the solenoid attracts the magnetic core C031 against the bias of the spring C028. Since the solenoid C031 immediately is deenergized, the spring C028 moves the pawl C027 upwardly to advance the shaft C012 and the associated brushes through one step and the brushes C010B and C024 respectively, engage the contacts C02 and C014. During the stepping operation, the self-stepping contacts C032 open and reclose without aflecting the operation of the system.

In an analogous manner, the three registered up floor calls at the first, second and fourth floors supply three successive pulses of energy to the solenoid COU31 for the purpose of advancing the stepping switch COU three steps. Thus, closure of make contacts 1UR8, 2UR8 and 4UR8 of the up floor-call registering relays complete energizing circuits for the solenoid COU31. Closure of contacts 1UR9, 2UR9 and 4UR9, respectively, energize the relays lURA, 2URA and 4URA. These relays open their contacts 1URA1, 2URA1 and 4URA1 to interrupt the energizing circuits established by the contacts 1UR8, ZURS and 4UR8, and thus three pulses are provided for the solenoid. The probability that two pulses may occur simultaneously is remote and may be disregarded. This advances the shaft COU12 three steps to bring the brush COU10 into engagement with the contact segment COU4.

The relay LT is assumed to be connected to the contact COU4. Consequently, the engagement of contact COU4 by the brush energizes the relay LT.

It will be assumed next that at this stage the capacitor CAP has charged to a value sutficient to fire the tube TB and pick up the relay TA. The relay TA closes its make contacts TA1 to establish with the break contacts REI a self-holding circuit.

The timing relay TA also closes its make contacts TA4 to establish with the stepping switches an energizing circuit for the reset relay RE. The reset relay opens its break contact R151 to deenergize the timing relay TA. In addition, make contacts RE2 close to establish with the resistor R9 a discharge circuit for the capacitor CAP. Closure of make contacts R153 establishes with the stepping switches a self-holding circuit for the resetting relay. Closure of the make contacts RES completes with the selfstepping contacts C032 a self-stepping circuit for the solenoid C031. Consequently, the switch C0 rapidly steps in a clockwise direction until the brush C024 engages the contact C023 to maintain energization of the solenoid C031. As the brush C024 leaves the contact segment C022, it is no longer effective for completing a self-holding circuit for the relay RE. In a similar manner, closure of the make contacts RE4 establishes a selfstepping circuit for the stepping switch COU and this resets until the brush COU24 leaves the contact COU22. Since the arms C024 and COU24 have passed respectively the contacts C022 and COU22, the reset relay RE is now deenergized. The make contact RES opens to deenergize the solenoid C031 and this permits the spring C028 to advance the shaft C012 one step to bring the brush C023 into engagement with the contact segment C013. In

During a resetting operation break contacts RE6 and RE7 open to prevent energization of the relays LT and UT during the resetting operation.

it will be recalled that the opening of the break contacts RE} resulted in dropout of the timing relay TA. Opening of the make contacts TA4 had no immediate effect on the operation of the system.

Returning to the effect of the dropout of the reset relay RE, this relay opens its make contacts REC. to interrupt the discharge circuit for the capacitor CAP and closes its break contacts REl to start another timing operation.

Turning now to the third and fourth parking relays it will be noted that the energization of these relays depends on the position of a walking earn switch WE. The walking beam of this switch is pivoted for rotation about an axis WBd and carries a movable contact WBa which is moved between two fixed contacts WBb and WBc. The third parking relay LTA is connected between the fixed contact WBb and the bus L. The fourth parking relay UTA is connected between the fixed contact WBc and the bus L. The movable contact WBa is connected to the bus L+ through a manually-operated switch SW4.

The position of the walking beam of the walking beam switch is controlled by a coil LTB having an armature connected pivotably to the left hand end of the walking beam and by a coil UTB having an armature connected pivotably to the right hand end of the Walking beam. One terminal of each of these coils is connected to the bus L+. The remaining terminals are connected respectively to the blades of a double-pole, double-throw manuallyoperated knife switch SW3. The upper terminals of the switch are connected to the bus L- respectively through the make contacts UT6 and LT4. The lower terminals of the switch are connected to the bus L- respectively through front contacts TSS2 and back contacts TSSl of a cam-operated switch TSS.

The contacts T SS1 and TSS2 are intended to be closed and open during predetermined periods of time. To this end they may be operated by any conventional time switch. For illustrative purposes it will be assumed that the switch is operated by a time wheel TSW which rotates in a clockwise direction as viewed in Figure 3 at the rate of one revolution per week. This wheel is divided into seven sectors, one for each day of the week, some of the days being indicated on their respective sectors. Each of the sectors may have one or more cams selected or adjusted to operate the switch during desired periods of time. For example, the Monday sector is illustrated as having two cams TSCI and TSCZ. The cam T SCI may be designed to operate the switch TSS to open the back contacts T881 and close the front contacts TSSZ during a period of time on Monday when a preponderance of travel in the down directions is expected. For example, this period of time may be between the hours of 7 and 9 in the morning.

If a second period during which such travel is expected occurs during the hours of 7 and 8 in the evening on Monday, the cam TSCZ may be designed to operate the switch TSS to open the back contacts T881 and close the front contacts TSS2 between the hours of 7 and 8 on Monday. In a similar manner cams may be associated with each of the other sectors for which pcriods are expected to occur regularly in which the travel on the elevator system is preponderantly in the down direction.

Operation For the first operation it will be assumed that the switch SW1 of Fig. 2 is in its upper position connecting the make contacts UTl and the switch TS across the contacts 5C2. The switch SW2 is assumed to be closed. The switch SW4 of Fig. 4 isassumed to be open and the components of Fig. 3 are assumed to be in the positions 8 illustrated immediately after a. reset operation. The capacitor CAP now starts to charge for the purpose of measuring the necessary resetting time for the stepping switches.

Returning to Fig. 2, it will be noted that the switches condition the system to establish the lower terminal floor as a parking station for elevator car A. As long as the elevator car A is at its parking station the switch LS is open. However, as soon as the elevator car A leaves the 1 lower terminal floor the switch LS closes as a result of movement of the cam TLS (Fig. l) away from the switch LS. Such closure connects the coil 10 for energization through the switch LS, the break contacts UT3 and the switch SW2. The energized coil 1C in effect registers a car call for the first floor and the elevator car'now must be returned to the first floor before it can be parked.

At this stage it will be assumed that down floor calls are registered in rapid succession for the fifth, fourth and third floors. The sequence for registering such floor calls will be understood from the aforesaid Carney et al. patent. The registration of the down floor calls for the fifth floor is accompanied by closure of the make contacts 5DR8 to complete with the break contacts 5DRA1 an energizing circuit for the solenoid C031 of the stepping switch CO. The registration of the down floor call also results in closure of the make contacts 5DR9 to energize the auxiliary relay 5DRA. The auxiliary relay thereupon opens its break contacts 5DRA1 to deenergize the solenoid C031. This permits the spring C028 to move the pawl C027 for the purpose of advancing the stepping switch brushes one step. Such movement of the brushes has no immediate effect on the operation of the system.

In a similar manner the registration of the down floor call for the fourth floor results in a second stepping operation of the stepping switch. The second stepping operation also has immediate effect on the operation of the system.

hould the time delay measured by the charge of the capacitor CAP expire at this time the stepping switches would reset in the manner previously described without affecting the operation of the system. However, it will be assumed that the time delay has not expired at the time the down floor call is registered at the third floor. The registration of the down floor call at the third floor produces a third operation of the stepping switch CO in the manner which will be understood from the foregoing discussion.

The brush C0103 now engages the contacts CO4 and with the break contacts RE7 establishes an energizing circuit for the first parking relay UT. The opening of the break contacts UT3 of Fig. 2 prevents a parking call to be registered for the lower terminal floor. The closure of the make contacts UTl establishes the upper erminal floor as the parking door. It will be noted that when the elevator car A is away from the upper terminal iloor the switch TS is closed for the reason that the cam I TLS of Fig. l is displaced from the switch TS. Consequently, the switch TS and the make contacts UTl together with the switch SW1 establish a shunt around the contacts 5C2 to register a parking call for the upper terminal floor by energization of the coil 5C. This is desirable for the reasons that the registration of a numher of down floor calls indicate a demand for service preponderantly in the down direction. Such service may 5 that the relay TA picks up to initiate a resetting operation of the stepping switches by the sequence previously discussed. Such resetting of the stepping switches results in deenergization of the parking relay UT. However, it will be assumed that this relay has a long delay in drop out which may be, for example, of the order of five minutes. If during the five minute delay in drop out of the relay UT a succession of calls requiring down travel of the elevator cars again brings the brush CO10B or the brush COllB into engagement with the contacts CO4 the relay UT will remain picked up for another period of five minutes. If during the five minute period calls requiring down travel of the elevator car are not received at a rate sufficient to reenergize the relay UT, the relay UT drops out. The resultant opening of the make contacts UTl of Fig. 2 accompanied by the reclosure of the break contacts UT3 again establishes the lower terminal floor as the parking station for the elevator car A. In a similar manner the opening of the make contacts UT2 and the closing of the break contacts UT4 establish the lower terminal floor as the parking station for the elevator car B.

Thus, it will be seen that the relay UT operates to establish the upper terminal floor as the parking floor only for the duration of a traific condition or service demand indicating a substantial demand for service in the down direction, and at all other times the lower terminal floor is the parking floor.

Next, it will be assumed that the switch SW1 of Fig. 2 is operated to connect the make contacts UTA1 and the switch TS' across the contacts 5C2. The switch SW2 is open. The switch SW3 is operated to its upper position as illustrated in Fig. 4. The switch SW4 is closed.

It will also be assumed that the walking beam switch WB is in the position illustrated in Fig. 4 and this means that the third parking relay LTA is energized and picked up. Consequently, the make contacts LTA1 of Fig. 2 are closed. Such closure selects the lower terminal floor as the parking station for the elevator car A. If the elevator car A is displaced from the lower terminal floor the make contacts LTA1 together with the switch LS establishes an energizing circuit for the coil 1C to register a call requiring the return of the elevator car A to the lower terminal floor before it can park. Closure of the make contacts LTA2 similarly selects the lower terminal floor as the parking station for the elevator car B.

It will be assumed next that down floor calls are registered at the fifth, fourth and third floors to bring the brush 0010B into engagement with the contact segment CO4 in the manner described above. This indicates a substantial demand for service in the down direction.

As a resut of its energization the relay UT closes its make contacts UT1 and UT2 and opens the break contacts UT3 and UT4. However, because of the positions of the switches SW1, SW2, BSWl and BSW2, the contacts UT1, UT2, UT3 and UT4 do not affect the operation at this time of the system. However, the closure of make contacts UT6 now establishes with the switch SW3 an energizing circuit for the coil UTB and the walking beam switch consequently moves the contact WBa into engagement with the fixed contact WBc. This results in energization of the fourth parking relay UTA. The operation of the walking beam switch also deenergizes the third parking relay LTA and this relay opens its make contacts LTA1 and LTA2 to discontinue the selection ofthe lower terminal floor as the parking floor.

The energization of the fourth parking relay UTA closes make contacts UTA1 and'UTAZ to select the upper terminal floor as the parking floor. Thus, if the elevator car A is displaced from the upper terminal floor the switch TS is closed and the coil 5C is energized through the switch TS' and the closed make'contacts UTA1 to register a call requiring return of the elevator car to the upper terminal floor before it can park. Similar comments apply to the elevator car B.

If a similar demand for service in the down direction occurs within the drop out time of the relay UT this relay remains picked up. However, if the demand for service in the down direction is insufficient for a five minute period to reenergize the relay UT this relay drops out. The reopening of the make contacts UTl and UT2 and the reclosure of the break contacts UT3 and UT4 have no etfect at this time on the operation of the system. The opening of the make contacts UT6 deenergizes the coil UTB but the walking beam switch remains in the position to which it was last operated and the deenergization of the coil UTB does not affect the operation of the system at this time.

it will be assumed next that after the walking beam switch has operated to select the upper terminal floor as a parking floor and after the relay UT has dropped out, a trafiic condition or service demand arises indicating a substantial demand for service in the up direction. For example, it will be assumed that the elevator car B is at the third floor set for up travel when a car call is registered for the fifth floor and that the elevator A is at' the first floor set for up travel when car calls are registered for the second and fifth floors. The sequence for registering such calls can be understood from the aforesaid Carney et al. patent.

The registration of the car call for the fifth floor in the elevator car B results in closure of the make contacts B5C6 of 3. Inasmuch as the elevator car is assumed to be set for up travel the make contacts BUP6 are closed. Consequently, an energizing circuit is established for the stepping switch COU which steps the switch one step from the position illustrated in Fig. 3. It will be assumed that the capacitor CAP has just started a measurement of a resetting period of the stepping switches. The car call also results in closure of make contacts B5C8 to energize the auxiliary relay BSCA. This relay may have a slight delay in pick up to assure prior pick up of the relay BUP. The relay BSCA opens its break contacts E5CA2 to terminate the energization of the stepping switch COU and this switch consequently completes its first stepping operation. If the reset period for the stepping switch COU expires before further advance of the stepping switch, the stepping switch is reset without operating the relay LT in the manner previously described. However, it will be assumed that prior to the expirationof the reset period the car calls registered in the elevator car A for the second and fifth floors result in two additional operations of the stepping switches COU in a manner which will be understood from the foregoing discussion. As a result of such stepping operations the brush COUlltlB engages the contacts C0134 to energize the relay LT through the break contacts RE6.

The second parking relay LT now closes its make contacts LT4 to complete with the switch SW3 an energizing circuit for the coil LTB. The energized coil LTB operates the walking beam switch WB back to the position illustrated in Fig. 4. The walking beam consequently moves the contact WBa away from the fixed contacts WBc to deenergize the fourth parking relay UTA. This relay opens its make contacts UTA and UTAZ to terminate the selection of the upper terminal floor as the parking floor. In addition, the walking beam switch engagesthe contacts WBa and WEI; to complete an energizing circuit for the third parking relay LTA. This relay recloses make contacts LTA1 and LTAZ to restore the selection of the lower terminal floor as the parking floor,

From this discussion it follows that the relays LTA and UTA, in response to a substantial service demand predominantly in one direction, select a parking floor and retain the selection until a substantial demand for service in the opposite direction occurs.

For the final operation it will be assumed that the switches SW1, SW2, BSWl and BSW2 are in the positions illustrated in Fig. 2, that the switch SW3 is oper- 1 1 ated to move the knife blades into engagement with the lower switch terminals in Fig. 4 and the switch SW4 is closed. This places the selection of a parking floor under the control of the time switch. With the switch TSS in the position illustrated in Fig. 3, the back contacts TSSl are closed and an energizing circuit is established through the switch SW3 for the coil LTB. This retains the walking switch SW1; in the position illustrated in Fig. 3. It will be recalled that when the walking beam switch is in the position illustrated the third parking relay LTA is energized and selects the lower terminal fioor as the parking floor. During certain periods of the day when substantial service in the down direction is expected, the switch T35 is operated to close its front contacts TSSZ. For example, in an apartment house a substantial demand for down service may occur between the hours of 7 to 9 in the morning when occupants leave the apartment house for their places of employment. Again in an apartment house a substantial amount of down service may occur between the hours of 7 to 9 in the evening following the dinner hour. As previously explained, cams such as the cams TSCl and T5302 for Monday are dimensioned and positioned to operate the switch 'lSS into position to close the front contacts T852 and open the back contacts TSSl during the desired periods of time. When the switch T35 is so operated it interrupts the energization of the coil LTB and completes an energizing circuit through the switch SW3 for the coil UTB. As a result of such change in energization of its coils, the walking beam switch WB operates to interrupt the energizing circuit for the third parking relay LTA and to establish an energizing circuit for the fourth parking relay UTA. From the preceding discussion it will be recalled that the drop out of the relay LTA followed by the pick up of the relay UTA selects the upper terminal floor as the parking floor for the elevator cars. A similar cam is selected and positioned on the wheel TSW to operate the switch TSS during each period for which the upper terminal floor is to be the parking floor.

Although the invention has been described with reference to certain embodiments thereof, numerous modifications falling within the spirit and scope of the invention are possible.

We claim as our invention:

1. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, and control means for moving the elevator cars and stopping the elevator cars at selected lioors, said control means comprising call registering means for registering calls for floors at which an elevator car is desired to stop, means responsive to call registration for moving and stopping at least one of the elevator cars to serve the call registration, said structure providing a plurality of parking stations each effective when selected for receiving one of the elevator cars when no call remains registered requiring further service, selecting means automatically effective during the operation of the elevator system to carry passengers for selecting a first period during which first ones of said parking stations are efiective and a second period during which second ones of said parking stations are effective to park the elevator cars, and parking means responsive to absence of call registration during said first period for initiating the parking of the elevator cars in the first ones of the parking stations, said parking means being responsive to absence of call registration during said second period for initiating the parking of the elevator cars in the second ones of the parking stations.

2. in an elevator system, a structure having a plurality f floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, and control means for moving the elevator cars and stopping the elevator cars at selected floors, said control means comprising call registering means for registering calls for floors at which an elevator car is desired to stop, means responsive to call registration for moving and stoppingat least one of the elevator cars to serve the call registration, said structure providing a plurality of parking stations each effective when selected for receiving one of the elevator cars when no call remains registered requiring further service, selecting means responsive to a first elevator trafiic condition encountered in the operation of said elevator cars for selecting a first period during which first ones of the parking stations are effective to park the elevator cars, said selecting means being responsive to a second elevator traffic condition encountered in the operation of said elevator cars for selecting a second period during which second ones of the parking stations are effective to park the elevator cars, and parking means responsive to absence of call registration during said first period for initiating the parking of the elevator cars in the first ones of the parking stations, said parking means being responsive to absence of call registration during said second period for initiating the parking of the elevator cars in the second ones of the parking stations.

3. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, and control means for moving the elevator cars and stopping the elevator cars at selected floors, said control means comprising call registering means for registering calls for floors at which an elevator car is desired to stop, means responsive to call registration for moving and stopping at least one of the elevator cars to serve the call registration, said structure providing a plurality of parking stations each effective when selected for receiving one of the elevator cars when no call remains registered requiring further service, selecting means comprising timing mechanism for selecting a first time period during which first ones of the parking station are effective for parking the elevator cars, and a second time period during which second ones of the parking stations are effective for parking the elevator cars, and parking means responsive to absence of call registration during said first period for initiating the parking of the elevator cars in the first ones of the parking stations, said parking means being responsive to absence of call registration during said second period for initiating the parking of the elevator cars in the second ones of the parking stations.

4-. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, and control means for moving the elevator cars and stopping the elevator cars at selected floors, said control means comprising call registering means for registering calls for floors at which an elevator car is desired to stop, means responsive to callregistration for moving and stopping at least one of the elevator cars to serve the call registration, said structure providing a plurality of parking stations each effective when selected for receiving one of the elevator cars when no call remains registered requiring further service, selecting means automatically effective during the operation of the elevator system to carry passengers for selecting a first period during which first ones of said parking stations are effective and a second period during which second ones of said parking stations are efiective to park the elevator cars, said selecting means comprising primary parking means for parking the elevator cars at the first ones of the parking. stations in the absence of call registrations, and secondary parking means responsive to a predetermined traflic condition for parking the elevator cars at the second ones of the parking stations in the absence of call registrations only for a period determined by the duration of said trafiic condition, said secondary parking means upon expiration of the last-named period restoring essence 13 the elevator cars to control by the primary parking means.

5. in an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, and control means for moving the elevator cars and stopping the elevator cars at selected floors, said control means comprising call registering means for registering calls for floors at which an elevator car is desired to stop, means responsive to call registration for moving and stopping at least one of the elevator cars to serve the call registration, said structure providing a plurality of parking stations each eifective when selected for receiving one of the elevator cars when no call remains registered requiring further service, selecting means responsive to a first elevator traffic condition encountered in the operation of said elevator cars for electing a first period during which first ones of the parking stations are effective to park the elevator cars and retaining such selection despite a change from the first elevator traific condition to a second elevator trafiic condition which does not satisfy the first elevator trafiic condition, said selecting means being responsive to a third elevator trafilc condition encountered in the operation of said elevator cars for selecting a second period during which second ones of the parking stations are effective to park the elevator cars, and parking means responsive to absence of call registration during said first period for initiating the parking of the elevator cars in the first ones of the parking stations, said parking means being responsive to absence of call registration during said second period for initiating the parking of the elevator cars in the second ones of the parking stations.

6. in an elevator system, a structure having a plurality of vertically-spaced floors, a plurality of elevator cars, means mounting the elevator cars for vertical movement relative to the structure to serve the floors, and control means for moving the elevator cars and stopping the elevator cars at selected floors, said control means comprising call registering means for registering calls for floors at which an elevator car is desired to stop, said call registering means comprising first call registering means for registering calls for each of a plurality of the fioors for elevator service in down direction, second call registering means for registering calls for each of a plurality of the floors for elevator service in the up-direction, and third call registering means for each of the elevator cars for registering calls for each of a plurality of floors desired by passengers in the elevator cars, means responsive to call registration for moving and stopping at least one of the elevator cars to serve the call registration, said structure providing first parking stations adjacent the upper ends of the paths of travel of the elevator cars and second parking stations adjacent the lower ends of the paths of travel of the elevator cars, and service demand means responsive to a first traffic condition indicating a substantial demand for down elevator service for conditioning the control means to park the elevator cars at the first parking stations in the absence of call registration, and service demand means responsive to a traific condition indicating a substantial demand for up elevator service for conditioning the control means to park the elevator cars at the second parking stations in the absence of call registration.

7. In an elevator system, a structure having a plurality of floors, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floors, and control means for moving the elevator car and stopping the elevator car at selected floors, said control means comprising call registering means for registering calls for floors at which the elevator car is desired to stop, means responsive to call registration for moving and stopping the elevator car to serve the call registration, said structure providing first and second parking stations for the elevator car, selecting means automatically effective during the operation of the elevator car to carry passengers selecting a first period during which the first parking station is effective to park the elevator car and a second period during Whiul'l a second parking station is effective to park the elevator car, and parking means responsive to absence of call registration during said first period for initiating parking of the elevator car at the first parking station, said parking means being responsive to absence of call registration during said second period for initiating parking of the elevator car at the second parking station.

8. In an elevator system, a structure having a plu rality of vertically-spaced floors, an elevator car, means mounting the elevator car for vertical movement relative to the structure to serve the floors, and control means for moving the elevator car and stopping the elevator car at selected floors, said control means comprising call registering means for registering calls for floors at which the elevator car is desired to stop, means responsive to call registration for moving and stopping the elevator car to serve to call registration, said structure providing upper and lower parking stations for the elevator car, means responsive to a first traffic condition indicating a substantial demand for down elevator service for rendering efiective the upper parking station, means responsive to a second traflic condition indicating a substantial demand for up elevator service for rendering effective the lower parking station, and means responsive to absence of call registration for parking the elevator car in the effective parking station.

9. In an elevator system, a structure having a plurality of vertically-spaced floors, an elevator car, means mounting the elevator car for vertical movement relative to the structure to serve the floors, and control means for moving the elevator car and stopping the elevator car at selected floors, said control means comprising call registering means for registering calls for floors at which the elevator car is desired to stop, means responsive to call registration for moving and stopping the elevator car to serve the call registration, said structure pro-,

viding upper and lower parking stations for the elevator car, timing means for selecting first and second periods of time, means rendering the upper parking station ef fective during the first periods and the lower parking station effective during the second periods, and means responsive to absence of call registration for parking the elevator car in the effective parking station.

10. In an elevator system, a structure having a plurality of vertically-spacedfloors, an elevator car, means mounting the elevator car for vertical movement relative to the structure to serve the fioors, and control means for moving the elevator car and stopping the elevator car at selected floors, said control means comprising call registering means for registering calls for floors at which the elevator car is desired to stop, means responsive to call registration for moving and stopping the elevator cal to serve the call registration, said structure providing first and second parking stations for the elevator car, first means responsive to a first traffic conditlon for rendering effective the first parking station and maintaining said first parking station efiective despite subsequent elimination of said traflic condition, means responsive to a second tratfic condition for rendering the second parking station effective and terminating the efiectiveness of the first parking station, and means responsive to absence of call registration for parking the elevator car in the efiective parking station.

No references cited. 

